Polyembryony, Biology

Assignment Help:

Polyembryony

Presence of more than one embryo in a seed is termed polyembryony. The phenomenon, first discovered in orange seeds by Leeuwenhoek (1719), attracted considerable attention because of its potential for application in and horticulture. Polyembryony is broadly classified into simple and multiple, depending on whether the supernumerary arises in one or more embryo sacs in the ovule. Simple polyembryony may be sexual or asexual. In sexual polyembryony embryos may originate from the fertilized egg and synergids, or by budding or cleavage of the polyembryony cells or suspensor of the zygotic embryo.

Asexual embryos are produced within the embryo sac without fertilization. Embryos may also originate from diploid nucellar or integumentary cells of the ode and grow into the embryo sac. These embryos are termed adventive or sporophytic. Multiple polyembryonies involve production of accessory embryos from two or more embryo sacs in the same ovule. For example, in the sea Island cotton, Gossypium barbadense, fertilization of egg in one embryo sac stimulates the induction of embryo from an unfertilized egg in the adjacent embryo sac within the same ovule. Thus, diploid-haploid twin embryos are produced in the seed.


Related Discussions:- Polyembryony

What is metallic implants, What is Metallic implants Metallic implants ...

What is Metallic implants Metallic implants undergo one or more several surface modifications to enable them to become suitable for implantation. These modifications are passiv

What is the relationship between these cells and hiv, Q. What are CD4 lymph...

Q. What are CD4 lymphocytes? What is the relationship between these cells and HIV? How does HIV replicate? The CD4 lymphocytes are T helper lymphocytes that present in their pl

What are the conventional signs used in genetic family trees, What are the ...

What are the main conventional symbols and signs used in genetic family trees? In genetic family trees the male sex is usually shown by a square and the female by a circle. Cro

What is this atp synthesis called, How in the respiratory chain do electron...

How in the respiratory chain do electrons from FADH2 and NADH2 passing through cytochromes liberate energy for the ATP synthesis? What is this ATP synthesis called? FADH2 and N

How infections and infestations cause pem, How Infections and Infestations ...

How Infections and Infestations cause PEM? Childhood infections (viral/bacterial) and parasitic infestations are almost always associated with PEM. These cause anorexia (loss o

How b and t cells recognize antigen are true explain, Which of the followin...

Which of the following statements about how B and T cells recognize antigen are true? a. B cells only recognize antigen presented by class I or class II MHC molecules. b. Both cell

What is microbodies , What is Microbodies ? Microbodies : Microbodi...

What is Microbodies ? Microbodies : Microbodies are formed by pinching off of vesicles from rough endoplasmic reticulum. They are not found in every cell, but are present a

How are the fruits formed, How are the fruits formed? The fecundation i...

How are the fruits formed? The fecundation is in angiosperms triggers the release of hormones that act upon the ovaries. The ovary wall after that it develops into a fruit that

Types of synovial joint, TYPES OF SYNOVIAL JOINT - 1 .      BALL AND ...

TYPES OF SYNOVIAL JOINT - 1 .      BALL AND SOCKET JOINT - One bone forms a ball like head that fits into a socket formed in the other bone. Movement is possible in al

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd